Explorando a extração verde de bioativos da Enterolobium contortisiliquum por solventes eutéticos: capacidade antioxidante e fotoprotetora

Abstract

The use of medicinal plants is one of the oldest traditional knowledge and, considering that a significant part of therapeutic drugs derives from natural products, interest in the search for innovative drugs has grown in recent years, causing an increase in the demand for extractions. The secondary metabolites present in plant species are responsible for biological activities and are generally extracted with conventional organic solvents, which are toxic, flammable, expensive and/or harmful to the environment. However, there are more sustainable alternatives for carrying out extraction, such as deep eutectic solvents, which have stood out for being biodegradable, cheap, easy to synthesize, reusable, non-toxic and that meet some of the principles of Green Chemistry and the Sustainable Development Goals of the 2030 Agenda. In this context, the southern region of Bahia is located in the Atlantic Forest, one of the most biodiverse forests in the world, which is home to numerous species with pharmacological potential that is still unknown or not very explored, such as Enterolobium contortisiliquum. However, it is also one of the most threatened areas, especially due to urban expansion. Therefore, this study aimed to synthesize and use deep eutectic solvents (DES) for the green extraction of bioactive compounds from Enterolobium contortisiliquum as a sustainable alternative to conventional solvents, in addition to analyzing the antioxidant activity, phenolic and flavonoid content, photoprotective activity and chemical profile of the extracts by liquid chromatography, aiming to compare the results of extraction with DES in comparison with conventional organic solvents: ethanol and methanol. For this, two DESs were synthesized: one composed of choline chloride and urea (DES 1) and another consisting of choline chloride, citric acid and water (DES 2), whose sustainability was evaluated through the Green Star. The results indicated that, in addition to meeting several principles of Green Chemistry and Sustainable Development Goals 9 and 12, the Star Fill Index (SPI) was 66.67 for DES 1 and 75.00 for DES 2, demonstrating the sustainability of the solvents. The DES demonstrated great extraction potential, with the DES of choline chloride and urea standing out as the most efficient. The species demonstrated photoprotective capacity, possibly attributed to the presence of antioxidant compounds. These results suggest the possibility of incorporating these extracts into sunscreen formulations, resulting in multifunctional products that combine antioxidant and photoprotective properties, in addition to reducing the use of synthetic and potentially harmful substances normally found in these formulations.